The present invention relates to a revolving tool carrying turret, provided with means for carrying out the unlocking and locking axial movements of the tool carrying body and for rotating said tool carrying body from a working position to the next working position.
Different revolving turrets are already known which at the periphery thereof bear, on a prismatic body or a disc, a plurality of working tools provided for carrying out predeterminent working operations in subsequent times.
Generally, the movements carried out periodically by said turrets are the following:
a revolving movement, with axial shifting, of a portion of the turret in order to unlock the tool carrying body from a fixed base of said turret;
a revolving movement of the tool carrying body in order to bring said tool carrying body from a position to the next one;
a positioning movement for positioning said tool carrying body, and
a reversing of the revolving movement in order to lock said tool carrying body on the fixed base, in its new working position.
As it is known these movements are achieved by using an electric motor, as driven by rotating-brush switches, or the like, driving, in turn, a screw coaxial with respect to the turret, which screw is able of revolving without axially moving.
The tool bearing body is connected to a nut screw, coupled to said screw and being provided, coaxially, with a ring gear coupled to an opposite ring gear, this latter being rigid with the base of the turret.
The rotation of said screw firstly causes said nut screw, being rigid with said tool carrying body, to axially move in such a way as to bring to contact the two opposite ring gears. Upon disengaging said ring gears, the tool bearing or carrying body is able of rotating and hence it can assume new angular positions, to bring the following tools to working positions.
For carrying out this rotation or revolving movement, upon having disengaged or unlocked said ring gears, in the known types of turrets different means and devices are provided acting to render mutually rigid one another said screw and nut screw in such a way that this latter, being rigid with the tool carrying body, is able of rotating through a predetermined angle as far as to reach its new working position. These known devices are, generally, of complex structure, rather larger size and frequently unable of permitting motors of suitable horse power to be installed.
Two turrets of the same applicant are also known, therein there is provided a fixed base and a revolving screw, being prevented from axially moving, engaging a nut screw rigid with the tool carrying body, the driving motor being coupled to an epicyclical reduction unit effective to provide, at first, the movement to the screw, to rise the turret, and then the revolving of the tool carrying body as far as to reach the new working position and, finally, the lowering movement of the turret.
These known turrets of the same applicant, while satisfactory from a mere operative point of view, are, however, of rather complex structure, mainly with respect to the stopping thereof, which requires a large space and rather intricate and easily wearable locking devices.